When setting up connections in communication networks there is generally a default route along which the connection is set up. For example, when placing a call from a mobile terminal attached to a mobile network in which a mobile terminal is roaming, the call will be set up via the network in which the mobile terminal is roaming.
The default route might not be the optimal route, e.g. in terms of cost effectiveness from the subscriber's point of view.
In prior art, this has e.g. been addressed by having a possibility of attaching the mobile terminal to another roaming network having lower prices. However, this requires the subscriber to be aware of the costs for placing calls from different roaming operators, which is cumbersome and unpractical.
Hence, in some prior art location based routing have been suggested, where a mobile terminal is provided with routing information and connections are established between the terminal and another terminal based on the location of the mobile terminal and the routing information dependent of the location of the terminal.
However, problems still remain, as location based routing generally requires alteration of call control functions in the communication devices in which it is to be implemented.
Hence, there is a need for location based routing which can be implemented in communication devices without the need to alter the call control functions in the communication devices.
Furthermore, the utilization of multiple local subscriber identity module (SIM) cards has also been suggested, i.e. allowing the use of local mobile subscriptions belonging to the network where the user currently is present. The advantage of using local SIM cards is that there is no extra charge (roaming charge) added to the call setup cost, and no extra cost of receiving calls, which is the case if the users home network SIM card would be used. Typically the rates of placing national calls also are much more beneficial if a local SIM card is used. Alternatively a dual mode telephone, i.e. a single device which logically includes two different phones which may each be attached to a different network, may be used instead of two SIM cards to avoid high calling costs. For example a dual mode mobile terminal may be a mobile terminal with GSM and Wireless LAN capabilities may be used.
A problem of using a local SIM card or dual mode phones is that each SIM card or logical phone in a dual mode phone is associated with a phone number to be used to reach the phone where the SIM card is used or logical phone is active. This means that if a user switches SIM cards in the mobile phone or activates a logical phone, all people communicating with the user need to be made aware of this new number. Merely diverting the calls directed to the normal phone number to the phone number of the local SIM would not lead to the desired cost saving. Another problem is that when the user calls other parties an unknown calling party number will be presented to the called party, that would expect the normal phone number of the calling party to be displayed.